Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
Very interesting data.
I'm happy to see the flat end plate to side wall joint is free of eddy currents crossing over, which means it is buildable with a removable end plate.
Plus the end plate fields look like TE01x, which is also good.
Nice work.
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
1) What is the numerical analysis package you are using ? (FEKO, etc.)
2) What numerical technique are you using to solve the equations? (Finite Element Method?, Boundary Element Method?, Finite Difference Method Space Domain?)?
3) What is the type of solution method?
A) Is it an eigensolution to the eigenvalue problem where there is no antenna in the model?
B) Or a steady state solution using an antenna and a spectral method to obtain a solution?
C) Or a transient solution using an antenna and a Finite Difference Time Domain to obtain a solution?
D) If you used an antenna, with a spectral steady-state solution or a transient Finite-Difference-Time-Domain solution, what was the type of antenna and where was it located?
4) What are the boundary conditions that you use in the model? Are you assuming a perfect conductor?
If not, how are you modeling an imperfect conductor like copper?
5) How is the quality factor (Q) calculated?
6) How are eddy currents calculated in the model?
Thanks
1. FEKO
2. MOM & FEM
3. ?
A. No, no eigenvalue calculation, magnetic Dipole (30mm above the flat plate at the central axis)
B. FEM
C. No FDTD
4.First time the boundary was defined to be PEC. Couldn't believe this numbers, therefore I used Copper, thickness 1mm for the second run (see diagrams).
Field pics are from the PEC-run.
5.No till now the Q is not calculated. My statement was due to the fieldstrength.
6. Good question, It's a internal calculation of FEKO, don't know their code
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is the numerical analysis package you are using ? (FEKO, etc.)
What numerical technique are you using to solve the equations? (Finite Element Method?, Boundary Element Method?, Finite Difference Method Space Domain?)?
What is the type of solution method? Is it an eigensolution to the eigenvalue problem where there is no antenna? Or a steady state solution using an antenna and a spectral method to obtain a solution?
Or a transient solution using an antenna and a Finite Difference Time Domain to obtain a solution?
What are the boundary conditions that you use in the model?
How is the quality factor (Q) calculated?
Thanks
Great questions Dr. Rodal!
I have a couple others.
Is the antenna your using a optimized point dipole from FEKO to excite the fields? If it is then the levels might not be real world and could be almost a order of magnitude to high. If that's the case then maybe running it with a loop or helical antenna will provide better data.
Shell
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What are the boundary conditions that you use in the model?
PEC. Coudn't belefe therefor I used Copper, thickness 1mm
How is the quality factor (Q) calculated?
Thanks
1. FEKO
2. MOM & FEM
3. ?
A. No, no eigenvalue calculation, magnetic Dipole (30mm above the flat plate at the central axis)
B. FEM
C. No FDTD
4.First time the boundary was defined to be PEC. Couldn't believe this numbers, therefore I used Copper, thickness 1mm for the second run (see diagrams).
Field pics are from the PEC-run.
5.No till now the Q is not calculated. My statement was due to the fieldstrength.
You should redo the parabola in all Cu, instead of the SS base plate, to compare apples to apples. It would also be good to see the Brady frustum with the same input conditions and no dielectric.
The pic below is 2 parabolas, both with the concentric focus at 2.5" above 0. I think this would work with a very high Q at around 1.5 GHz.
Another Q: What was the input power set to?
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What are the boundary conditions that you use in the model?
PEC. Coudn't belefe therefor I used Copper, thickness 1mm
How is the quality factor (Q) calculated?
Thanks
1. FEKO
2. MOM & FEM
3. ?
A. No, no eigenvalue calculation, magnetic Dipole (30mm above the flat plate at the central axis)
B. FEM
C. No FDTD
4.First time the boundary was defined to be PEC. Couldn't believe this numbers, therefore I used Copper, thickness 1mm for the second run (see diagrams).
Field pics are from the PEC-run.
5.No till now the Q is not calculated. My statement was due to the fieldstrength.
You should redo the parabola in all Cu, instead of the SS base plate, to compare apples to apples. It would also be good to see the Brady frustum with the same input conditions and no dielectric.
The pic below is 2 parabolas, both with the concentric focus at 2.5" above 0. I think this would work with a very high Q at around 1.5 GHz.
Another Q: What was the input power set to?
Dang it Todd, you're to sharp! You posted just about the same design I was just drawing. No need now. I do like this design.
Shell
...
1. FEKO
2. MOM & FEM
3. ?
A. No, no eigenvalue calculation, magnetic Dipole (30mm above the flat plate at the central axis)
B. FEM
C. No FDTD
4.First time the boundary was defined to be PEC. Couldn't believe this numbers, therefore I used Copper, thickness 1mm for the second run (see diagrams).
Field pics are from the PEC-run.
5.No till now the Q is not calculated. My statement was due to the fieldstrength.
Can you please re-post this great analysis, images and response regarding analysis method in "NASASpaceFlight.com Forum » General Discussion » New Physics for Space Technology » Resonant Cavity Space-Propulsion: ..." thread so that it does not get lost and can be referred to for future reference?
The dissipation only occurs at the interior surface. There is no dissipation in the inner volume.
Hence to minimize dissipaton in a given volume one has to minimize the surface/volume ratio.
A sphere is theoretically the volume that minimizes Surface/Volume ratio so it makes sense that a truncated sphere should have a higher Q than a truncated cone.
For a given volume, the object with the smallest surface area (and therefore with the smallest SA:V) is the sphere, a consequence of the isoperimetric inequality in 3 dimensions.
https://en.wikipedia.org/wiki/Surface-area-to-volume_ratioAlso, for all these solids, the surface-area-to-volume ratio decreases with increasing volume, so the bigger the EM Drive (regardless of the shape, including a sphere), the better.
...
1. FEKO
2. MOM & FEM
3. ?
A. No, no eigenvalue calculation, magnetic Dipole (30mm above the flat plate at the central axis)
B. FEM
C. No FDTD
4.First time the boundary was defined to be PEC. Couldn't believe this numbers, therefore I used Copper, thickness 1mm for the second run (see diagrams).
Field pics are from the PEC-run.
5.No till now the Q is not calculated. My statement was due to the fieldstrength.
Can you please re-post this great analysis, images and response regarding analysis method in "NASASpaceFlight.com Forum » General Discussion » New Physics for Space Technology » Resonant Cavity Space-Propulsion: ..." thread so that it does not get lost and can be referred to for future reference?
A sphere is theoretically the volume that minimizes Surface/Volume ratio so it makes sense that a truncated sphere should have a higher Q than a truncated cone.
For a given volume, the object with the smallest surface area (and therefore with the smallest SA:V) is the sphere, a consequence of the isoperimetric inequality in 3 dimensions.
https://en.wikipedia.org/wiki/Surface-area-to-volume_ratio
Also, for all these solids, the surface-area-to-volume ratio decreases with increasing volume, so the bigger the EM Drive (regardless of the shape, including a sphere), the better.
Yes, it true like they say bigger is better . . . but I'd be hard pressed to build a ~3 foot large base diameter ~900MHz Drive Dr. Rodal. Although it intrigues me enough to think it might be in the cards sometime in the future and how I could do it.
Could I fit it into my Covair...? hmmm. Na, that's too silly.
Shell
PS: The reason I posted this is the need to keep our heads in a realistic mode and while flying cars might be in dreams we're far from the reality of it.
...
You're close to the truth. Those are used to mislead and deceive. R & D improvement work has never been stopped, all the information provided on this forum are carefully studied and adopted by these teams.
I just see a lot of misinformation being thrown about. There has never been a verifiable em-drive thrust. Everything I have seen shows a 100% thermal signature. While I am sure you are well intentioned and trying to be sincere it is well known that the Chinese government does not tolerate spies. If there really was a breakthrough all attempts would be made to prevent you from reporting anything about it.
Is that what you are claiming with regards to the new NASA result, that's it's not a verified result?
Here are a few calcs based on the 88k Qu of my spherical end plate frustum based on copper construction.
Cu Rs ~8,000 uOhm at room temp & 2.45GHz Offered YBCO thin film at Rs 3uOhm at 77K (LN2) at 2.45GHz.
As Qu scales linear with Rs, the 8,000/3 = 2,667 should increase Qu by 2,667 or 88k to 2.35x10^8. As force scales with Q, the predicted 0.4N/kWrf increases to 1,067N/kWrf.
Instead of using LN2, using LHe cooling should drop the Rs 13x, which could increase force to 13,868N/kWrf.
Gotta love YBCO, KISS spherical end plate frustums & EmDrives.
...
Yes, it true like they say bigger is better . . . but I'd be hard pressed to build a ~3 foot large base diameter ~900MHz Drive Dr. Rodal. Although it intrigues me enough to think it might be in the cards sometime in the future and how I could do it.
Could I fit it into my Covair...? hmmm. Na, that's too silly.
Shell
PS: The reason I posted this is the need to keep our heads in a realistic mode and while flying cars might be in dreams we're far from the reality of it.
Shell, is somebody working on to your knowledge, or has somebody proposed a ~3 foot large base diameter ~900MHz ? Or is that a design that you have been working on secretly?
I don't recall people discussing such a large EM Drive. Do you recall, however, about a year ago, a group from Canada, (I think they were in Alberta) discussing working with their local University on a very high power experiment using megawatts? I don't recall hearing anything back from them...
The reason I posted this is the need to keep our heads in a realistic mode and while flying cars might be in dreams we're far from the reality of it.
All that is required is the application of EmDrive Enginerring.
The relationships between mode, freq, Df, Qu, Pwr & Rs are known. YBCO thin films with Rs of 3uOhms at 2.45GHz at 77K are commercially available.
While most may not accept Roger's theory, the equations do work to build EmDrives & predict the 2 forces that are generated and have been measured by many.
I have 5 Cu & Al frustums of various design in fabrication or finished. My next 2 frustum builds will be YBCO coated variants of the Al spherical end plate frustum driven by 100W and 250W Rf amps with very tight freq tracking from lowest reflected power, highest static force generation and highest acceleration.
Time waits for no one.
...
Yes, it true like they say bigger is better . . . but I'd be hard pressed to build a ~3 foot large base diameter ~900MHz Drive Dr. Rodal. Although it intrigues me enough to think it might be in the cards sometime in the future and how I could do it.
Could I fit it into my Covair...? hmmm. Na, that's too silly.
Shell
PS: The reason I posted this is the need to keep our heads in a realistic mode and while flying cars might be in dreams we're far from the reality of it.
Shell, is somebody working on to your knowledge, or has somebody proposed a ~3 foot large base diameter ~900MHz ? Or is that a design that you have been working on secretly?
I don't recall people discussing such a large EM Drive. Do you recall, however, about a year ago, a group from Canada, (I think they were in Alberta) discussing working with their local University on a very high power experiment using megawatts? I don't recall hearing anything back from them...
No. I'm not fully working on it just some thoughts on paper and if I knew of someone I would keep the confidentiality if I was asked to do so.
I've not heard much at all from the Canadians but my goodness it was a giant leap in about everything.
Best,
Shell
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is the numerical analysis package you are using ? (FEKO, etc.)
What numerical technique are you using to solve the equations? (Finite Element Method?, Boundary Element Method?, Finite Difference Method Space Domain?)?
What is the type of solution method? Is it an eigensolution to the eigenvalue problem where there is no antenna? Or a steady state solution using an antenna and a spectral method to obtain a solution?
Or a transient solution using an antenna and a Finite Difference Time Domain to obtain a solution?
What are the boundary conditions that you use in the model?
How is the quality factor (Q) calculated?
Thanks
Great questions Dr. Rodal!
I have a couple others.
Is the antenna your using a optimized point dipole from FEKO to excite the fields? If it is then the levels might not be real world and could be almost a order of magnitude to high. If that's the case then maybe running it with a loop or helical antenna will provide better data.
Shell
Yes the source was a magnetic dipole. It would be nice if I could use a more complex antenna but it's not supported by the FEKO students version I am currently using. There are still limitations, but a little less than FEKO lite. Such an antenna shape needs a lot of triangles in the mesh.
Even with this source, each of the shown calculations tooked several hours to converge.
I can still compare the results with older simulations when using the same source and conditions.
...
Yes, it true like they say bigger is better . . . but I'd be hard pressed to build a ~3 foot large base diameter ~900MHz Drive Dr. Rodal. Although it intrigues me enough to think it might be in the cards sometime in the future and how I could do it.
Could I fit it into my Covair...? hmmm. Na, that's too silly.
Shell
PS: The reason I posted this is the need to keep our heads in a realistic mode and while flying cars might be in dreams we're far from the reality of it.
Shell, is somebody working on to your knowledge, or has somebody proposed a ~3 foot large base diameter ~900MHz ? Or is that a design that you have been working on secretly?
I don't recall people discussing such a large EM Drive. Do you recall, however, about a year ago, a group from Canada, (I think they were in Alberta) discussing working with their local University on a very high power experiment using megawatts? I don't recall hearing anything back from them...
I brought up the 900 MHz cavity as an idea to play with in AutoCAD (I'm currently taking courses to become a draftsman). To my knowledge, no one is actually building one yet; I'm just trying to learn as I go.
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is your RF input power?
Is there anyone who has study a half-sphere shaped resonator regarding the emdrive?
In contrast to a parabolic one (where the focal depth for rays much shorter than the size of the structure itself was equal to the point where the baseplate was present).
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1607020#msg1607020
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is the numerical analysis package you are using ? (FEKO, etc.)
What numerical technique are you using to solve the equations? (Finite Element Method?, Boundary Element Method?, Finite Difference Method Space Domain?)?
What is the type of solution method? Is it an eigensolution to the eigenvalue problem where there is no antenna? Or a steady state solution using an antenna and a spectral method to obtain a solution?
Or a transient solution using an antenna and a Finite Difference Time Domain to obtain a solution?
What are the boundary conditions that you use in the model?
How is the quality factor (Q) calculated?
Thanks
Great questions Dr. Rodal!
I have a couple others.
Is the antenna your using a optimized point dipole from FEKO to excite the fields? If it is then the levels might not be real world and could be almost a order of magnitude to high. If that's the case then maybe running it with a loop or helical antenna will provide better data.
Shell
Yes the source was a magnetic dipole. It would be nice if I could use a more complex antenna but it's not supported by the FEKO students version I am currently using. There are still limitations, but a little less than FEKO lite. Such an antenna shape needs a lot of triangles in the mesh.
Even with this source, each of the shown calculations tooked several hours to converge.
I can still compare the results with older simulations when using the same source and conditions.
meep also has a magnetic dipole and when Q's on the orders of 100 of millions arise by using it, it makes the sims we see come under question. Although it takes more time to do a real antenna and you're limited by the mesh count it will be more realistic.
Shell
Monomorphic , did you calculate Q values for these ...would you tell us what you came up with THNX FL
Monomorphic , did you calculate Q values for these ...would you tell us what you came up with THNX FL
I have not had the time to run the necessary sweep to calculate the Q for all three of these cavities.
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is your RF input power?
No power scaling
This is the default setting. If this option is selected, FEKO will calculate the results using the specified source magnitudes.
Source magnitude is shown in the pic I have posted.
Now I did an FEA with the half-sphere shape. What I found is a massive fieldstrength, much higher than I ever have observed in the sims before. The Q should be very high.
What is your RF input power?
No power scaling
This is the default setting. If this option is selected, FEKO will calculate the results using the specified source magnitudes.
Source magnitude is shown in the pic I have posted.
Okay thanks. Are you doing sweeps using the continuous interpolated range or linearly spaced discrete points?
Have you had problems with the solutions converging using interpolated?
And what are your solver settings?
